Re: Problems with equalizeHist function

[Andrey Pavlenko]

what OpenCV version do you use?

I've checked the latest 2.4.3.2 and the code works OK with minimal modifications:

 Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.wshed_exp);
 
 Mat rgbMat = new Mat();
 Utils.bitmapToMat(bmp, rgbMat);
 
 Mat grayMat = new Mat();
 Mat bwMat = new Mat();
 
 Imgproc.cvtColor(rgbMat, grayMat, Imgproc.COLOR_RGB2GRAY);
 Imgproc.equalizeHist(grayMat, grayMat);
 
 Imgproc.threshold(grayMat, bwMat, 127.5, 255.0, Imgproc.THRESH_OTSU);
 Utils.matToBitmap(bwMat, bmp);

Just in case: some OpenCV version contained a bug in equalizeHist() that caused its crash in case of picture width isn't multiple of 4.